A fuel cell system usually comprises at least one fuel cell for generating electric current from cathode air and reformate gas. Such a fuel cell is usually composed of a plurality of individual fuel cell elements, which are stacked on one another and can also be called a fuel cell stack. To generate reformate gas, the fuel cell system may be equipped with a reformer, which generates the reformate gas from a fuel and reformer air. The fuel is usually a hydrocarbon. The reformate gas contains hydrogen gas and carbon monoxide. The fuel cell system may be equipped, in addition, with an air supply means, which draws in ambient air by means of an air delivery means from the surrounding area of the fuel cell system and splits this air at least into reformer air and cathode air. The reformer air can then be fed to the reformer via a reformer air line, while the cathode air can be fed to the at least one fuel cell via a cathode air line of a cathode side. Furthermore, provisions may be made in such a fuel cell system for sending anode gas of an anode side of the at least one fuel cell in the direction of the reformer by means of a recirculating line in order to thus make it possible to return anode waste gas from the respective fuel cell to the reformer. A hot gas delivery means, which contains a hot gas path, through which the anode waste gas flows, may be arranged in the recirculating line to drive the anode waste gas.
The respective fuel cell may be advantageously configured as an SOFC fuel cell, where SOFC stands for Solid Oxide Fuel Cell. Such an SOFC may also be called a high-temperature fuel cell. Comparatively high temperatures may consequently develop during the operation of such an SOFC. In particular, the recycled anode waste gas may be relatively hot as well, so that the hot gas delivery means arranged in the recirculating line is exposed to a high thermal load. To reduce the thermal load of the hot gas delivery, it is possible to cool the recycled anode gas by means of a corresponding heat exchanger. However, the apparatus necessary for this is relatively complicated.